As the invaders explored the abandoned nest interior, they gathered a few newly hatched adult workers too weak to run out of the nest with their older nestmates. All these captives the Streamsider raiders carried back unharmed to their own nest, a few to be eaten but most to be kept as slaves. Their captors took advantage of a trait basic to all kinds of ants: the individual slaves learned and thereafter accepted the odor of the colony in which they lived during the first several days following their emergence from pupa into active adult life. In that brief period the Trailheader callows acquired the odor of the Streamside Colony. From that time those who were brought into the Streamsider nest and survived being cannibalized became part of the slave-maker colony. They would thereafter live on equal terms with their captors, attacking any ant with a different odor.
By adopting the young adults at the age they learned the colony odor, the victorious Streamsider Colony added to its labor force with no great effort. The slaves--and that is what they were, because they served the victors entirely--made up for some of the Streamsider workers lost in battle.
Had the Trailhead Queen been alive during the war and captured by the Streamsider raiders, she would have been torn to pieces immediately. No queen of a defeated ant colony is allowed to live one unnecessary minute. The ant mind is remorseless in its insistence upon absolute sovereignty. No colony in power, and especially no alien queen, can be tolerated, because it is a threat to that sovereignty. It follows that any alliance between colonies is also out of the question. The absolute imperative of the nest site is the heart of the superorganism's life. The first law of ant colonial existence is that the territory must be protected at any cost.
There were forces, however, above and outside the colony's frame of reference. Just three weeks before, after their victory over the Trailheaders, the Streamsiders' nest had been visited by the moving trees. The event was similar to that experienced by the defeated Trailhead Colony the previous year. The giants came from nowhere, they departed abruptly without any reason understandable to ants, and they left behind vast quantities of strange food on the ground. The conjunction of all these events, and the magnitude of the gift, made the inexplicable visitors the equivalent of benevolent gods to the Streamsiders. The ants counted the coming of the gods as special to themselves, indeed a great blessing. True to the rules of learning by association, which applies to ants as it does to men, they also saw the gods as part of their extended society: They think like us (there is no other way to think, or way to conceive of another way to think about thinking), and they are part of our power.
The Streamsiders had defeated the Trailheaders, and then, as a parallel of some Old Testament tribe wiping out a defeated people, they committed myrmicide, the ant equivalent of genocide. Total destruction ensured, as for the Roman conquerors at Carthage, that their rivals would never rise again. Now the Streamsiders spread throughout the conquered territory, laying their own odor trails and marking the ground everywhere with moist spots of feces, which contained the territorial pheromone with substances particular to them. But they did not occupy the spacious nest interior of their defeated enemy. They were content for the time being to maintain headquarters in the mother nest. They patrolled their new territory to harvest food consisting variously of prey, sugary sap-sucker excrement, and arthropod corpses. The increased supply allowed the Streamside Colony to grow more rapidly in size.
They had been summoned, and they came unknowingly to die as needed. They conquered and enslaved, and occupied the land their tribe coveted. They were obedient to their instincts, and successfully completed the cycle necessary for the survival of their species.
23
AT THIS TIME, to the east of the triumphant Streamside Colony, along the shore of Dead Owl Cove farther away from the trailhead, and still unknown to the Streamsiders, an ominous change had come upon the environment. The sounds of birds and singing insects were no longer heard. Fewer squirrels, voles, and other mammals foraged across the quitted land. Butterflies and other pollinators of the ground plants were close to extinction.
The suppressing agent was a population explosion of ants. They belonged to the same species as the Streamsiders and other anthill builders living along the shore of Lake Nokobee, but had undergone a simple hereditary change with profound social consequences. So great was the mutation that they seemed outwardly to be a different species. Colonies that once contained up to ten thousand workers and a single mother queen had been replaced by Supercolony, a single gigantic society composed of millions of workers and thousands of queens. With no territories to defend, no tournaments to hold, no competition for food across its vast domain, Supercolony packed all the habitable ground with multiple interconnected nests.
Its foragers continuously patrolled every square foot. They explored tunnels and crevices in the soil. They checked every earthworm and beetle-grub burrow. They ate every spider that could be pulled from its web. They tolerated no other kind of ant in their domain. Unlike the ordinary anthill colonies of the Streamsiders and others of their same species, they ventured far up the trunks of the surrounding longleaf pines and searched through the lower branches. Supercolony patrolled, as no ordinary anthill colony ever had, the sparse understory of shrubs and high perennials. It turned a substantial part of the upland longleaf savanna on Lake Nokobee's shore into an otherwise lifeless carpet of ants.
Ant empires like this one have cropped up from time to time in different parts of the world. A similar transformation, introduced by a mutant colony accidentally introduced from South America, had swept through the fire ants after the species had occupied most of the southern United States. The origin of the Nokobee Supercolony was due to a change in only one gene in the hereditary code of the ants. The mutation did not create new processes in the brain and sensory system. Instead, it shut a couple of them down. Supercolony was much less sensitive to colony odors than others of its species. Although it could still distinguish the odors of other kinds of ants and nonmutated colonies of its own species, it was unable to make territorial divisions within its own borders.
By weakening Supercolony's sense of smell, the mutation also diminished the workers' ability to detect the queen odor. As a result a multitude of queens were now tolerated, in contrast to the single mother queen allowed in nonmutated colonies. These queenlets, as they might be called, were distributed widely through the webwork of galleries and chambers of the vast Supercolony nest. The queenlets were also smaller in size than nonmutant queens. They did not fly away to mate, and they made no effort to start new colonies of their own. Instead, at the mating hour they simply copulated with males they met on the nest surface, including their own brothers as well as cousins of varying degrees of remove, and then returned immediately to the nest interior to take up the production of more eggs for the growth of Supercolony.
A genetic mistake and a physical disability were for Supercolony ironically the key to success. The erasure of internal territories, combined with perpetual refreshment of the supply of queens, made Supercolony both boundless in size and potentially immortal. The mutation also gave it the power to extract far more resources from its environment than was possible for unmutated colonies of the same species. The ants had more space in which to pack their nests. Their dense populations allowed them to subdue more insects and arthropods as prey, and they were able to eliminate other ant species that competed with them for food.
The mutation had changed not only the social structure of its carriers but also the rules of engagement in war. The myrmidons of Supercolony fell upon rival colonies like a Mongol horde. By early spring in the year following the Streamside Colony victory over the Trailhead Colony, the first Supercolony patrols reached the eastern boundary of the newly secured Streamsider territory. The first workers to encounter the patrols had no conception of what they were now facing. It was nothing less than the greatest natural threat imaginable for these ants. Supercolony armies expanded their own domain by the simple process of building nests
on newly conquered land and then sending forth scouts to explore the terrain a relatively short distance beyond. When a large enough expeditionary force could be assembled on the border to confront whatever colonies stood in their way, they attacked their neighbors without hesitation.
As Supercolony scouts appeared with increasing frequency, their counterparts from the Streamside Colony offered to hold a tournament. In the ancient ritual of their species, they puffed up their abdomens, straightened their legs into stilts, and tried to strut around the intruders. Supercolony scouts did not respond in kind. If alone, they fled immediately, laying an odor trail homeward to recruit reinforcements. If already present in groups, they attacked at once.
After a few days of such sorties and mismatched responses, the ants of the closest Supercolony nests reached a level of ant power and excitement sufficient for a military expedition. By this time some of the scouts had already pressed forward and discovered the Streamsider nest itself. The odor trails they laid, the alarm pheromones they broadcast, and the scent of enemy on the bodies of the scouts returning home brought even more Supercolony workers to the frontier. The number of Supercolony fighters able to invade grew faster and faster. For a little while longer Streamsider defenders suggested a tournament. They were answered with unhesitating aggression from the Supercolony invaders.
Finally, the Streamsiders dropped the diplomatic response and began to fight back on contact. It was too late and too little for the unfortunate defenders. By this time the invading horde was unstoppable. In the course of a single day a wave of lethal fighting spread across the approaches to the Streamsider nest entrance. The jaws that serve as the hands of ants in times of peace and prosperity were now the swords of battle wielded with abandon by overwhelming numbers of the Supercolony invaders. The stings through which the ancestor wasps laid eggs were now poison-tipped stilettos of predation and war.
Within a few hours the ground was covered with severed limbs and dead and injured ants from both sides. The supply of fighters was limited for the Streamside Colony, as usual for their species, but not for Supercolony. The Supercolony army on the field increased as that of Streamsider declined. The minor workers among the defenders started to pull back into the nest, while many of the soldiers formed a circle around the nest entrance, heads facing outward, in the characteristic maneuver of their kind. The tactic, which often works for a strong colony facing another strong colony with the same methods of war, utterly failed this time. The Supercolony force grew to a size never seen in ordinary combat practiced by Nokobee mound ants.
The attackers broke through the Streamsider soldier ring and poured into the interior of the nest. They pressed downward into the labyrinth of subterranean chambers and galleries, subduing and killing every inhabitant they found. They located the mother Queen in the lowermost chamber, huddled beneath a mass of her praetorian soldier guards and minor worker nurses. The invaders pulled off the defenders and killed them all. A dozen seized and spread-eagled the Queen. A soldier cut off her head, and others began to drag her body upward on its long journey to the Supercolony nest, to serve as food. Barely an hour after they had launched the final assault on the Streamsider nest entrance, the battle was over.
The conquerors did not take any of the Streamsider pupae and newly emerged workers alive. Because of the prodigious reproductive capacity of their own colony, especially when enjoying the resources of newly conquered terrain, they had no need of slaves. They killed all the young captives on the spot and carried their bodies back to the Supercolony nest for food.
Only a few Streamsiders managed to escape the final battle and hide in nearby vegetation. Like the Trailheader refugees their own colony had driven out, most died within hours.
Other colonies along the Nokobee lakeside suffered the same fate during the remainder of the summer. By midsummer, the species and most of the rest of antdom across a quarter mile of shore at Dead Owl Cove had been replaced by a continuous, gigantic Supercolony. The ant empire had conquered all. Now there settled a strange new calm upon the region.
Peace and the stability of empire had come to this little parcel of the longleaf pine savanna. No more fighting among colonies of their species, no more wars, no more conflict within the colony over who had the right to reproduce. No more colony boundaries of any kind. Forget the old way of depending on a mother queen. There was now an abundance of surplus queenlets to take her place, any one of which could die without noticeable consequence. Peace across the land, perfect equality among all its citizens, and potential immortality for the empire were the rewards from a change in social structure.
In this one stroke, by intervention of a single micromutation, an era had ended and a new one begun. This part of the Nokobee ecosystem had been shifted in its governance and in the quality of its life.
24
YET, EVEN WITH its triumph, the Supercolony empire was not healthy. It was out of balance with nature. Its huge, dense population was too heavy a burden for the habitat to carry. Many kinds of plants and animals within reach of the worker swarms began to decline, and a few disappeared altogether. Among the first to suffer were other kinds of ants. Those that occupied soil nests similar to that of Supercolony were driven away, or killed and eaten. Those that depended on similar kinds of food found their supplies declining. Their scouts and harvesters were beaten to new food sites by the ubiquitous Supercolony workers. Spiders and ground beetles that once ranked among the chief predators of the Nokobee anthill species were now themselves hunted down as prey.
Supercolony workers were driven by the need for ever more food to supply the unrestrained egg production of the queenlets and the nurseries of hungry grublike larvae located throughout the giant nest. They penetrated parts of the surrounding environment once shunned as dangerous and unproductive by others of their species. They hunted along the waterline, a habitat dangerous for ants. They climbed the trunks of the trees and combed the lower branches, cleaning out caterpillars, sawfly larvae, tree crickets, and any other living thing that could be caught and killed. They captured or unintentionally frightened away pollinators of flowering plants, including the diversity of butterflies, moths, bees, wasps, hoverflies, and flower beetles that once swarmed over the area.
A small number of species were able to stand up to the onslaught of the new myrmidons. Among them were the most heavily armored of the beetles, centipedes, and millipedes. Also relatively safe were mites, springtails, and other arthropods too small to serve as prey. Earthworms were both elusive and shielded by their thick mucus. These survivors were the equivalent of the house sparrows, rock pigeons, and rats that thrive around humans, each either unpalatable or hard to catch.
A very few creatures did love Supercolony and were loved in return. These were the scale insects, aphids, and mealybugs, delicate and sluggish little insects that pierce plants with hollow beaks and suck out the sap. They were protected by the ants in the same manner and for the same reasons that humans cultivate domestic animals. Supercolony nurtured herds of the sap-suckers throughout its domain. The protection the ants provided against sap-sucker enemies, such as ichneumonid wasps that laid eggs in the bodies of the sap-suckers, and ladybird beetles able to kill and eat the little insects outright, allowed the herds to grow abnormally large. The sap-suckers stunted the growth of the infested plants, causing their leaves to turn yellow and drop off.
Unfettered through the absence of all but a few competitors, freed from most ant-eating predators, Supercolony increased not only in total population but also in density. It came to pass that there were simply more ants per square foot than could be supported by the Lake Nokobee shore. What was once a scattering of nests separated by open space was now a nearly continuous ant city. The problem of meeting Supercolony's ravenous needs was basically the same as supporting an overpopulated human city.
By late summer, the growth of Supercolony had already begun to falter. The ecosystem as a whole, their life support system, was suffering. Many of the surviving
plants were too weak to set seed. Ground-foraging animals, including brown thrashers, flickers, squirrels, rabbits, voles, lizards, and snakes, avoided the area. They were repelled as much by the scarcity of food as by the bites and stings they were forced to endure when they tried to forage among the aggressive ants.
Supercolony also had become a subject of talk among humans. Picnickers and fishermen who visited Dead Owl Cove steered around the heaped-up soil of its hundreds of nests. The original formicid inhabitants, including the now-vanished Trailheader and Streamsider Colonies, had been scarcely noticed in previous years. Only a few people, usually children, paused to look at the conspicuous but scattered mound nests. Now everyone paid attention to the amazing Supercolony. "It is," they agreed, "a new kind of ant out there, worse than fire ants." Some added, "What's needed is purely and simply an exterminator."
Supercolony had mastered the environment, subdued its rivals and enemies, increased its space, drawn down new sources of energy, and raised the production of ant flesh to record levels.
The truth, nonetheless, was that Supercolony did not have permanent control of Dead Owl Cove. In the long train of ecological time it was guaranteed only a few seasons of success. By trading sustainability of the home for wider dominance, its genes had made a terrible mistake. A price had to be paid, first by the ecosystem and then, with its support systems declining, by Supercolony itself. Life for Supercolony was at its maximum that summer, in the season of maximum growth, but the quality of its life was falling. It owed to nature a debt of energy and materials incurred by overconsumption, the payment of which might be postponed for a little while, especially if Supercolony could conquer more territory--but then it must conquer still more, and yet more, to maintain what it had. The debt could also be postponed if its workers discovered new sources of food on the occupied territory. Yet even that unlikely event would merely increase the density of the population, and the debt would only be increased, not retired.
Anthill Page 17